There are cases where you need to upload files that need to be accessible by anyone. For example you have an icon or images you want to send in emails.
In the app builder under App > Files you can upload files that can be accessed through
a public URL. For example if you upload a file logo.png at the images folder, you will
be able to get it with this URL:
https://<app>.slingrs.io/<env>/runtime/api/files/public/images/logo.png
Public files are part of the metadata of the app. This means that they will be synced to production. It is recommended to only put there small files you might need, otherwise this will slowdown syncing changes. If you need to upload big files like videos, please use other storage services.
Although new apps will have three folders by default (documents, images and misc) you
can organize files as you need by creating or changing folders.